Developmental and Cytochemical Features of Female Gametophyte in Endemic Lathyrus undulatus (Fabaceae)

Abstract

The presented study describes developmental and cytochemical features of female gametophyte in Lathyrus undulatus Boiss. (Fabaceae), which belongs to subfamily Papilionoideae and is endemic to northwestern Turkey. The ovary is monocarpellate and the mature ovule is anatropous, bitegmic and crassinucellate. Differentiation of the outer integument determines a Y-shaped micropyle aperture. The nucellar epidermis is poorly developed. The inner parietal layers of the integument differentiate into a thin layer of endothelium. The hypodermally oriented archesporium is distinguished as one cell. Archesporium produces a parietal cell and a primary sporogenous cell. The primary sporogenous cell enlarges to form megasporocyte. After meiotic division, megaspores organize in an isobilateral manner of tetrad. Only one megaspore functions and it is one of the chalazal members of the tetrad. The functional megaspore develops into an embryo sac, which gives rise to a Polygonum type. The synergids lying above the egg cell are typical in structure. The antipodals are ephemeral and degenerate earlier without leaving any remnants. Embryo development is of Onagrad type. Suspensor degenerates at the globular embryo stage. The primary endosperm nucleus divides mitotically in a free nuclear manner and it is rich for insoluble polysaccharides and protein. (C) 2013 Friends Science Publishers